I've had the code for this in CakesFW for a while now, but I've decided to separate it and make it a standalone project.
This is a mostly drop-in replacement for Gateway's LauncherTemplate.dat you see in projects like rxTools and Decrypt9.
What this does, is, from whatever entry point you're coming, does some exploits to get into ARM9 kernel mode, and then runs your code.

Pretty neat, although I feel like a universal payload launcher would be a better idea than a template for various projects to inject into. Like the homebrew launcher, but for ARM9. Would avoid .dat naming conflicts and make entrypoint compatibility easier.

Pretty neat, although I feel like a universal payload launcher would be a better idea than a template for various projects to inject into. Like the homebrew launcher, but for ARM9. Would avoid .dat naming conflicts and make entrypoint compatibility easier.

Not a bad idea. I may implement it someday. Though my priorities lie somewhere else at the moment.

Not a bad idea. I may implement it someday. Though my priorities lie somewhere else at the moment.

AFAIK, cpasjuste already made something that does this. The piece of software he made is called CtrBootManager. (Did you really miss out on it or did I misunderstood something? I'm not sure...)
Edit: Oh, I've just seen the dates, sorry then. Edit 2: Solved by visiting dukesrg.no-ip.org/3ds